Ultimate Technique (Revision 139)

The first place you can unlock this achievement / trophy is Day 1 of Ninja Gaiden 3's Story Mode.

Story Mode

The Ultimate Technique is a special Technique that Hayabusa uses. After killing enough enemies and taking enough damage, your Ki Gauge will fill and your Katana will glow red. Hold down the Strong Attack button until a red wind flows around you, then release it to unleash a barrage of attacks on multiple targets nearby.